Ex-F1 driver Christian Klien and F2 champion Andy Soucek are both chasing the remaining two race seats in Formula One this season.

US F1 and Campos still haven't confirmed their second drivers, and Klien and Soucek both claim to be in negotiations with the teams ahead of the season opener in Bahrain on March 14.

"The chances are still good," said Klien. "Until I no longer see a realistic chance, I will fight to take part in F1. Another year as a reserve driver would not be a catastrophe."

He added that he had been in the running for both the Sauber seat taken by Pedro de la Rosa and the Renault position filled by Vitaly Petrov right up until the final announcements. He has also decided not to pursue a drive at Le Mans this year, after competing for Peugeot in 2008 and 2009, as the 24-hour event clashes with the Canadian Grand Prix.

Soucek, who had previously said he did not have the budget to drive for Campos, has now announced that his negotiations with the Spanish team are at an "advanced stage", while his talks with US F1 are more informal.

"Right now nothing is signed but the negotiations have opened new fronts," said Soucek. "The two empty seats are with US F1 and Campos, but there are other possibilities, all of them in F1. I think to be third driver is a job I deserve, and I do not have to pay for it. I'm interested in that."

Both face competition from Superleague champion Adrian Valles, who has been widely tipped as a favourite for the US F1 seat. He was a contender for a drive at Spyker in 2007 to replace Christijan Albers but was beaten to the spot by Marcus Winkelhock and Sakon Yamamoto.

"I'm sorry, I can't talk. I just hope things don't go wrong," Valles was quoted as saying by local media last week.

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